Cylinder to cylinder balancing using intake valve actuation

Abstract

A method and apparatus for balancing a combustion phasing between a plurality of cylinders located in an engine. The method and apparatus includes a determining a combustion timing in each cylinder, establishing a baseline parameter for a desired combustion timing, and varying actuation of at least one of a plurality of intake valves, each intake valve being in fluid communication with a corresponding cylinder, such that the combustion timing in each cylinder is substantially equal to the desired combustion timing.

1. A method for adjusting a combustion timing of a cylinder in an engine, comprising the steps of:
 determining a pressure variation in the cylinder; and  
 varying actuation of an intake valve fluidly communicated to the cylinder until the pressure variation is a desired pressure variation, the desired pressure variation being indicative of a desired combustion timing.  
 
   
   
     2. A method, as set forth in  claim 1 , wherein the engine includes a plurality of cylinders, and further including the steps of:
 determining a pressure variation in each cylinder; and  
 varying actuation of each of a plurality of intake valves fluidly communicated to a corresponding cylinder until the pressure variation of each cylinder is a desired pressure variation.  
 
   
   
     3. A method, as set forth in  claim 2 , wherein varying actuation of each of a plurality of intake valves includes the step of varying an open duration of each of the plurality of intake valves. 
   
   
     4. A method, as set forth in  claim 2 , further including the step of determining a heat release variation from each corresponding pressure variation. 
   
   
     5. A method, as set forth in  claim 4 , further including the step of varying actuation of at least one of the plurality of intake valves until the heat release variation of a corresponding at least one cylinder is a desired heat release variation. 
   
   
     6. A method, as set forth in  claim 2 , wherein determining a pressure variation includes the step of sensing a pressure in at least one cylinder. 
   
   
     7. A method, as set forth in  claim 6 , wherein determining a pressure variation includes the steps of:
 sensing a pressure in at least one cylinder; and  
 calculating a pressure in at least one other cylinder.  
 
   
   
     8. A method for adjusting a combustion timing of a first cylinder in an engine relative to a second cylinder in the engine, comprising the steps of:
 determining a first parameter indicative of a combustion pressure in the first cylinder;  
 determining a second parameter indicative of a combustion pressure in the second cylinder; and  
 varying actuation of at least one of a first intake valve and a second intake valve associated with respective first and second cylinders until the first and second parameters are substantially equal.  
 
   
   
     9. A method for adjusting a combustion timing of each of a plurality of cylinders in an engine, each cylinder having a respective intake valve, comprising the steps of;
 determining a plurality of parameters indicative of respective combustion pressures in each cylinder; and  
 varying actuation of at least one of the intake valves until all of the plurality of parameters have substantially equal values.  
 
   
   
     10. A method, as set forth in  claim 9 , further including the steps of:
 establishing a baseline parameter as a function of the determined plurality of parameters; and  
 varying actuation of at least one of the intake valves until all of the plurality of parameters are substantially equal to the baseline parameter.  
 
   
   
     11. A method, as set forth in  claim 10 , wherein varying actuation of at least one of the intake valves includes the step of varying an open duration of at least one of the intake valves. 
   
   
     12. An apparatus for adjusting a combustion timing of each of a plurality of cylinders located in an engine, comprising:
 a plurality of intake valves, each intake valve in fluid communication with a corresponding one of the plurality of cylinders and being independently actuable;  
 means for determining a plurality of parameters, each parameter being indicative of a combustion pressure in each respective cylinder; and  
 a controller for receiving signals associated with the plurality of parameters and responsively varying actuation of at least one of the intake valves until all of the plurality of parameters have substantially equal values.  
 
   
   
     13. An apparatus, as set forth in  claim 12 , wherein the means for determining a plurality of parameters includes at least one cylinder pressure sensor. 
   
   
     14. An apparatus, as set forth in  claim 13 , wherein the means for determining a plurality of parameters includes a plurality of cylinder pressure sensors, each of the cylinder pressure sensors being associated with a corresponding one of the plurality of cylinders. 
   
   
     15. A method for balancing a combustion phasing between a plurality of cylinders located in an engine, comprising the steps of:
 determining a combustion timing in each cylinder;  
 establishing a baseline parameter for a desired combustion timing; and  
 varying actuation of at least one of a plurality of intake valves, each intake valve being in fluid communication with a corresponding cylinder, such that the combustion timing in each cylinder is substantially equal to the desired combustion timing.  
 
   
   
     16. A method, as set forth in  claim 15 , wherein determining a combustion timing in each cylinder includes the step of sensing a combustion timing in each cylinder. 
   
   
     17. A method, as set forth in  claim 16 , wherein sensing a combustion timing in each cylinder includes the step of sensing a pressure variation in each cylinder. 
   
   
     18. A method, as set forth in  claim 15 , wherein determining a combustion timing in each cylinder includes the steps of:
 sensing a combustion timing in at least one cylinder; and  
 calculating a combustion timing in at least one other cylinder as a function of the sensed combustion timing.  
 
   
   
     19. A method, as set forth in  claim 15 , wherein varying actuation of at least one of a plurality of intake valves includes the step of varying an open duration of at least one of a plurality of intake valves. 
   
   
     20. A method for balancing a combustion phasing between a plurality of cylinders located in an engine, comprising the steps of:
 determining a combustion timing in each cylinder;  
 calculating a heat release rate in each cylinder as a function of the combustion timing;  
 establishing a baseline parameter for at least one of a desired combustion timing and a desired heat release rate; and  
 varying actuation of at least one of a plurality of intake valves, each intake valve being in fluid communication with a corresponding cylinder, such that at least one of the combustion timing and the heat release rate in each cylinder is substantially equal to a corresponding at least one of the desired combustion timing and the desired heat release rate.